That is the link... he wont tell anyone how he made it. And i dont kno enough about air cannons to kno how to make what he made. If you watch the video, he somehow hooked it up so when you press the button on the AT4, it fires the projectile. I was thinking it was a type of piston exuast cannon. But how he made the valve and everything??? idk it just blows my mind.

Anyone kno how to make this... Or can give me detailed instructions on how to make one myself?? thanks

Yea, it looks like a coaxial piston. He proably used some electric activating valve (normally a sprinkler valve is electricly actuated). Im confused to as how the pressure is created. Is there some CO2 or air connection that I missed? Sorry I got tired of reading the article half way through or so...

yea lol. It cant kill people. Well i guess it would be cool to make it so you could switch it around and put somethen more destructive in there, and then for airsoft switch back to the non lethal PAC.

Yea thats the part i cant figure out is his whole entire wireing and everything. I dont know of any electric valve that could fit inside 3 inch pipe like that. Crazy design. I like how its so compact tho.

I don't think it's simmilar to the mini-pump. Firstly, he states that it "has provisions for on-feild filling". This seems to imply that it's not a primary goal of the design, as an intergral thing like the mini-pump would be.Secondly, I see no way to pump it.Thirdly, a pump system like that would have a pretty long reload time - enough to make it pointless, probably.

It's probably a pilot-valve system, although I'm not sure of the method of actuation. Perhaps he is using the firing pin to depress a popet valve or blowgun.

Essentialy, in a poppet valve you have a piston-like contraption that is forced onto the seal by pressure behind it, like this:

------,air ||----o------'

When you push on the "o" (the end of a rod sticking out of the piston), the piston is pushed in, and the air can flow around it and to atmophere.I was thinking that he might be using the firing pin to depress a poppet valve being used as the pilot valve.A shraeder valve is esentialy a small popet valve.